Federal regulations require that all workers within the right-of-way of a federal aid highway who are exposed either to traffic or to construction equipment within the work area wear high-visibility safety apparel. This requirement applies to firefighters and other emergency workers who are often required to wear other highly specialized protective garments, such as fire, heat, chemical and/or biohazard resistant protective garments depending upon the particular emergency situation they are responding to, and are sometimes required to also wear specialized breathing apparatus, such as a self-contained breathing apparatus (SCBA) having a backpack mounted oxygen/air tank.